Yesterday Apple has just pushed out iOS 4.3.4 and the main goal of this release is to fix the hole of JailbreakMe 3.0 to stop jailbreaking of the iPad 2 jailbreaking. Fortunately iOS 4.3.4 is jailbroken already on iPhone, iPad, iPod touch using PwnageTool Bundle and this tipb by Redmondpie.

The neat thing about PwnageTool is that it allows you to preserve your iPhone’s baseband, which aids in unlocking your iPhone later on using Ultrasn0w unlock. In this guide we’ll show you how you can jailbreak your iPhone on iOS 4.2.4, preserve your baseband and unlock it with Ultrasn0w.

There is no unlock for iOS 4.3.4’s baseband, hence do not hit the update button in iTunes if you rely on a carrier unlock.

Your baseband will be preserved during the whole process.

This jailbreak is semi-tethered.

Hacktivation is fully supported

Modify PwnageTool

Step 1: Download the custom PwnageTool bundle for iPhone 4 from this link. (Please DO NOT hotlink this file. These bundles have been created by Redmond Pie. Credit the original source. Thanks)

Extract the .zip on your desktop, and inside it you should see a .bundle file. For this guide we’re going to use the iPhone 4 bundle, you should choose the one that applies to your device. Move the .bundle file to your desktop.

Step 2: Download PwnageTool 4.3.3 and then copy it to the /Applications directory. Right click on the PwnageTool icon and then click on Show Package Contents.

Step 3: Now you’re going to navigate to the following address:Contents/Resources/FirmwareBundles/ and paste the .bundle file which you copied to your desktop in this location.

Build Custom iOS 4.3.4 Firmware

Step 4: Download iOS 4.3.4 from this link tailored for your iOS device and save it on your desktop.

Step 5: Fire up PwnageTool in Expert mode and select your device as show in the screenshot below:

Step 6: Now you’re going to browse for the iOS 4.3.4 firmware for your device, direct it to the location where you downloaded the iOS 4.3.4 file.

Step 9: Now you’re going to put your iOS device in DFU mode, follow the on screen steps on how to do so, they are as follows:

Hold down the Power and Home buttons simultaneously for 10 seconds.

Let go of the Power button but keep on holding the Home button for 10 seconds.

If you followed the steps correctly, then you’re in DFU mode.

Restore Your Device to iOS 4.3.4 Using iTunes

Step 10: Start up iTunes on your Mac and select your device from the sidebar on the left. Hold down the “alt” key on your keyboard and click on “Restore”, do not press “Update” or “Check for Update”.

Now a pop up window will appear, simply guide it to the jailbroken custom iOS 4.3.4 file which was created by PwnageTool, then click Open.

Step 11: From this point onwards, iTunes will do its thing and restore your device to the jailbroken iOS 4.3.4 custom firmware file. Don’t do anything crazy at this point, just let iTunes complete its job. When everything is done, your device will boot up into a custom jailbroken version of iOS 4.3.4.